When preparing and administering drugs care has be taken to minimize, or preferably eliminate the risk of exposing people, such as medical and pharmacological personnel, to toxic substances. Safety boxes, cabinets or isolators are often used to prepare drugs to reduce the risk of toxic substances leaking into breathable air. However, such facilities require a lot of space, they are non-portable and can be expensive to install, maintain and repair.
Some drugs must be dissolved or diluted before they are administered, which involves transferring a solvent from one container to a sealed vial containing the drug in powder or liquid form, by means of a needle for example. Drugs may be inadvertently released into the atmosphere in gas form or by way of aerosolization, during the withdrawal of the needle from the vial and while the needle is inside the vial if any pressure differential between the interior of the vial and surrounding atmosphere exists.
This problem may be eliminated or at least minimized by using a pressure equalization device that may be attached to a vial during the preparation of drugs. The pressure equalization device comprises a gas container in communication with the interior of the vial, which ensures that neither an increased pressure nor a vacuum can occur inside the vial when gas or liquid is injected into or withdrawn from the vial. The gas container may be filled with cleaned or sterilized air prior to its use to ensure that the contents of the vial do not become contaminated with air-borne particles such as dust, pollen, mould or bacteria and other undesirable substances.